1# @ohos.application.Want (Want) 2 3Want is a carrier for information transfer between objects (application components). Want can be used as a parameter of **startAbility()** to specify a startup target and information that needs to be carried during startup, for example, **bundleName** and **abilityName**, which respectively indicate the bundle name of the target ability and the ability name in the bundle. When ability A needs to start ability B and transfer some data to ability B, it can use Want a carrier to transfer the data. 4 5> **NOTE** 6> 7> The APIs of this module are supported since API version 8 and deprecated since API version 9. You are advised to use [@ohos.app.ability.Want](js-apis-app-ability-want.md) instead. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8 9## Modules to Import 10 11```ts 12import Want from '@ohos.application.Want'; 13``` 14 15## Attributes 16 17**System capability**: SystemCapability.Ability.AbilityBase 18 19| Name | Type | Mandatory| Description | 20| ----------- | -------------------- | ---- | ------------------------------------------------------------ | 21| deviceId | string | No | ID of the device running the ability. | 22| bundleName | string | No | Bundle name. If both **bundleName** and **abilityName** are specified in a **Want**, the **Want** can directly match the specified ability.| 23| abilityName | string | No | Name of the ability. If both **bundleName** and **abilityName** are specified in a **Want** object, the **Want** object can match a specific ability. The value of **abilityName** must be unique in an application.| 24| uri | string | No | URI information to match. If **uri** is specified in a **Want** object, the **Want** object will match the specified URI information, including **scheme**, **schemeSpecificPart**, **authority**, and **path**.| 25| type | string | No | MIME type, that is, the type of the file to open, for example, **'text/xml'** and **'image/*'**. For details about the MIME type definition, see https://www.iana.org/assignments/media-types/media-types.xhtml?utm_source=ld246.com. | 26| flags | number | No | How the **Want** object will be handled. By default, numbers are passed in. For details, see [flags](js-apis-ability-wantConstant.md#wantconstantflags).| 27| action | string | No | Action to take, such as viewing and sharing application details. In implicit **Want**, you can define this attribute and use it together with **uri** or **parameters** to specify the operation to be performed on the data. | 28| parameters | {[key: string]: any} | No | Want parameters in the form of custom key-value (KV) pairs. By default, the following keys are carried:<br>- **ohos.aafwk.callerPid**: PID of the caller.<br>- **ohos.aafwk.param.callerToken**: token of the caller.<br>- **ohos.aafwk.param.callerUid**: UID in [bundleInfo](js-apis-bundle-BundleInfo.md#bundleinfo-1), that is, the application UID in the bundle information.<br>- **component.startup.newRules**: whether to enable the new control rule.<br>- **moduleName**: module name of the caller. No matter what this field is set to, the correct module name will be sent to the peer.<br>- **ohos.dlp.params.sandbox**: available only for DLP files. | 29| entities | Array\<string> | No | Additional category information (such as browser and video player) of the ability. It is a supplement to the **action** field for implicit Want. and is used to filter ability types. | 30 31**Example** 32 33- Basic usage 34 35 ```ts 36 let want = { 37 'deviceId': '', // An empty deviceId indicates the local device. 38 'bundleName': 'com.extreme.test', 39 'abilityName': 'MainAbility', 40 'moduleName': 'entry' // moduleName is optional. 41 }; 42 this.context.startAbility(want, (error) => { 43 // Start an ability explicitly. The bundleName, abilityName, and moduleName parameters work together to uniquely identify an ability. 44 console.log('error.code = ' + error.code) 45 }); 46 ``` 47 48- Data is transferred through user-defined fields. The following data types are supported: 49 50 * String 51 ```ts 52 let want = { 53 bundleName: 'com.example.demo', 54 abilityName: 'com.example.demo.MainAbility', 55 parameters: { 56 keyForString: 'str', 57 }, 58 }; 59 ``` 60 * Number 61 ```ts 62 let want = { 63 bundleName: 'com.example.demo', 64 abilityName: 'com.example.demo.MainAbility', 65 parameters: { 66 keyForInt: 100, 67 keyForDouble: 99.99, 68 }, 69 }; 70 ``` 71 * Boolean 72 ```ts 73 let want = { 74 bundleName: 'com.example.demo', 75 abilityName: 'com.example.demo.MainAbility', 76 parameters: { 77 keyForBool: true, 78 }, 79 }; 80 ``` 81 * Object 82 ```ts 83 let want = { 84 bundleName: 'com.example.demo', 85 abilityName: 'com.example.demo.MainAbility', 86 parameters: { 87 keyForObject: { 88 keyForObjectString: 'str', 89 keyForObjectInt: -200, 90 keyForObjectDouble: 35.5, 91 keyForObjectBool: false, 92 }, 93 }, 94 }; 95 ``` 96 * Array 97 ```ts 98 let want = { 99 bundleName: 'com.example.demo', 100 abilityName: 'com.example.demo.MainAbility', 101 parameters: { 102 keyForArrayString: ['str1', 'str2', 'str3'], 103 keyForArrayInt: [100, 200, 300, 400], 104 keyForArrayDouble: [0.1, 0.2], 105 keyForArrayObject: [{obj1: 'aaa'}, {obj2: 100}], 106 }, 107 }; 108 ``` 109 * File descriptor (FD) 110 ```ts 111 import fs from '@ohos.file.fs'; 112 let fd; 113 try { 114 fd = fs.openSync('/data/storage/el2/base/haps/pic.png').fd; 115 } catch(e) { 116 console.log('openSync fail:' + JSON.stringify(e)); 117 } 118 let want = { 119 'deviceId': '', // An empty deviceId indicates the local device. 120 'bundleName': 'com.extreme.test', 121 'abilityName': 'MainAbility', 122 'moduleName': 'entry', // moduleName is optional. 123 'parameters': { 124 'keyFd':{'type':'FD', 'value':fd} 125 } 126 }; 127 this.context.startAbility(want, (error) => { 128 // Start an ability explicitly. The bundleName, abilityName, and moduleName parameters work together to uniquely identify an ability. 129 console.log('error.code = ' + error.code) 130 }); 131 ``` 132 133 <!--no_check--> 134
